Recently, persons having obesity or a little higher blood sugar level caused by the ingestion of high calorie food and overeating or lack of exercise, so-called reserve group of diabetes mellitus, have been increasing. As a prevention of this, supplements aimed at suppressing sugar absorption and fat absorption are on the market. In addition, for the purpose of suppressing high blood sugar level and preventing diabetes mellitus, α-glucosidase inhibitors which suppress formation of glucose from starch and oligosaccharides are also on the market.
For the purpose of preventing obesity, prevention of overeating by controlling ingesting calories and consumption of calories by constant exercise are necessary, but their everyday practice is difficult in reality. In addition, the α-glucosidase inhibitors are effective not only as a therapeutic agent for diabetes mellitus but in dissolving obesity caused by overeating and lack of exercise and diet control. However, these agents (e.g., acarbose (mfd. by Bayer, trade name Gulcobay)), voglibose (mfd. by Takeda Chemical Industries, trade name Basen) and the like) are difficult to obtain, and when these are taken, absorption of polysaccharides into the body can be suppressed but absorption of glucose and the like monosaccharides cannot be suppressed, so that significant sugar absorption-suppressing effect cannot be expected. In addition, problems of various side effects occur sometimes after their taking. Because of this, concern has been directed for the development of a safe and inexpensive natural-origin composition.
As a natural material effective in satisfying such a requirement for obesity and sugar absorption suppression, there are plants of the genus Salacia. The root and trunk of a plant of the genus Salacia have been used as a natural drug by a traditional medical science, aayurveda, in India and Sri Lanka. It has been handed down in Sri Lanka that the root skin of Salacia reticulata is effective in treating rheumatism, gonorrhea and a skin disease and is also used in the treatment of initial stage diabetes mellitus. In India, a root of Salacia oblonga is used in similar treatments, and it is said that Salacia chinensis is also used in the treatment of diabetes mellitus (FOOD Style 21, vol. 6, no. 5, pp. 72-78).
Thus, it has been handed down that plants of the genus Salacia are effective in the prevention and early stage treatment of diabetes mellitus. In recent years, it has been reported that a plant of the genus Salacia has the action to suppress increase of blood sugar level, and its action mechanism is the sugar absorption suppressing action based on the α-glucosidase activity inhibition (FOOD Style 21, vol. 6, no. 5, pp. 72-78).
In addition, there are patents on the compounds which are contained in the extraction components of the genus Salacia and have the action to inhibit α-glucosidase activity (Japanese Patent No. 3030008, JP-A-2004-323420 and JP-A-2000-86653), and their application examples and patents as anti-diabetic agents based on the α-glucosidase activity inhibitory action (JP-A-9-301882 and Japanese Patent No. 3261090).
Since the sucrase inhibitory activity of most of the supplements on the market which use Salacia extract powder is standardized as 250 μg/ml or less, and when their sucrase inhibitory activity is actually measured, it is mostly about 350 μg/ml, so that it is necessary to increase the number of tablets in order to ingest effective amount.
Concern has been directed toward the development of a high concentration Salacia extract powder, for the purpose of decreasing the number of tablets by increasing blending amount of Salacia extract powder per tablet.
In addition, it is known that a large quantity of catechins as a kind of polyphenols are contained in the flavonoid-containing tea extract to be used in the invention. Anti-oxidation action, bactericidal action, anticancer action, blood pressure lowering action, blood sugar level suppressing action and the like many physiological actions have been reported on such catechins, and in recent years, effectiveness of the fat combustion for its somatic fat reducing effect has further been reported (Shimotoyodome A., et al., Med. Sci. Sport Exerc., 37, 1884-1892, 2005 and Murase T., et al., Int. J. Obes. Relat. Metab. Disord., 30, 561-568, 2006).
It has been reported that the effect to decrease body weight and somatic fat (abdominal total fat area, visceral fat area) can be seen by the ingestion of high concentration catechin for a prolonged period of time. It is considered that a fat combusting enzyme in cells of the liver is activated by the high concentration catechin and thereby increase energy consumption by activating the fat metabolism, thus resulting in the reduction of somatic fat (Tsuchida T., Itakura H., Nakamura H., Prog. Med., 22, 2189-2203, 2002, Hackett A. M., et al., Eur. J. Drug Metab. Pharmacokinet, 8, 35-42, 1983, Murase T., et al., Int. J. Obes. Relat. Metab. Disord., 26, 1459-1464, 2002 and Ota N., et al., J. Health. Sci., 51, 233-236, 2005).
It is possible to ingest catechin by drinking a green tea or the like tea, but since the content per cup is small, it is necessary to ingest a tea extract powder in the form of tablets or capsules for ingesting a desired amount.
In addition, a tea extract contains catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate as catechins, or epigallocatechin gallate, epigallocatechin, epicatechin gallate and gallocatechin in order of the content.
In addition, the flavonoid to be used in the invention is roughly divided into flavonols, isoflavones and catechins. Among these, flavonols are a general term of polyphenols, and particularly among them, anti-oxidation action, bactericidal action, anticancer action, immune action, fat combustion and the like many physiological actions have been reported on resveratrol, and further, its effectiveness for fat combustion has been confirmed. Also, effectiveness of the life-prolonging effect of mice which ingested a high calorie feed supplemented with resveratrol has been reported (Science. 275, 218, (1997) and Nature. Nov. 16th. (2006)).
It is possible to ingest resveratrol by drinking or eating a grape extract or drinking red wine or the like, but since the content per once is small, it is necessary to drink a large volume of red wine or ingest it in the form of tablets or capsules for ingesting a desired amount.
In addition, vitamin C absorption support, anti-oxidation action, immune action and the like physiological actions have been reported particularly on quercetin among polyphenols, and it was further confirmed that this is effective in suppressing fat absorption (JP-T-2001-524119 (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application) and WO 01/076580).
It is possible to ingest quercetin by eating an onion, but since the content per once is very small because the skins are not generally used for food. In order to ingest required amount, it is necessary to eat an onion including its skins or ingest its extract powder in the form of tablets or capsules.
Recently, many anti-obesity and after meal blood sugar level increase suppressing foodstuffs have been on the market, and a large number of patents have been applied regarding sugar absorption suppression and fat absorption repression and fat combustion (Japanese Patent No. 3261090, JP-A-2005-295991, JP-A-2006-160710, JP-A-2006-280236 and JP-A-2007-131620). However, very little actually is known about the foodstuff which shows both of the effects on the sugar and fat absorption suppression and the fat combustion by a small amount of ingestion.